dzavla lujvo

x1 [word/text] is a noun (a word referencing a thing (generic sense) and syntactically functioning as such) with meaning/referent x2 in language x3

Nounness is an inherent property of the single word or phrase coupled with its meaning (although other such properties may exist for the word/phrase alone); it is not merely a role being assumed: the word with that meaning always is a noun in the language.